Very Strange Non Start Issue When Cold

[AdDaMan]

Originally Posted by Helmsman

Yeah your voltage should be good to start the car. For ref mine is typically just under 12v after opening and still start right away (too little driving and no pwr outlet available).

Have you managed to confirm that its not the starter motor that goes nuts in low temp?

Thanks. I have not, no.

[Helmsman]

Originally Posted by AdDaMan

Thanks. I have not, no.

And btw after replacing your battery twice, ever noticed more than say 12.4v when you've opened the car? (i.e. stuff start to drain) Never been more than so for me even with new batteries, in fact typically 12.3v with load on a new/charged battery.

And what voltage do you measure with engine started?

[AdDaMan]

Originally Posted by Helmsman

And btw after replacing your battery twice, ever noticed more than say 12.4v when you've opened the car? (i.e. stuff start to drain) Never been more than so for me even with new batteries, in fact typically 12.3v with load on a new/charged battery.

And what voltage do you measure with engine started?

Nope, i'd say that 12.5v is the max you tend to see. Not sure where people get these other numbers from.

[AdDaMan]

Just gone out to the car, 4 weeks later. 11.8v.
WTFFFFFFFFF

[RocketyMan]

Originally Posted by AdDaMan

Just gone out to the car, 4 weeks later. 11.8v.
WTFFFFFFFFF

Yup! That's completely typical. Either put the battery on a tender or disconnect it if leaving it for long storage.

[AdDaMan]

Originally Posted by RocketyMan

Yup! That's completely typical. Either put the battery on a tender or disconnect it if leaving it for long storage.

Can’t do either unfortunately.
It’s parked outside around the back in a private car park. Can’t leave it unlocked and can’t leave it on a drip charge 😕

[DrFerry]

Originally Posted by AdDaMan

I am already on my 3rd battery. It is CATEGORICALLY not the battery at fault.

Go and get a Battery Tender. The E9X M3 is basically a rolling cyborg. It has approximately 12 different on board computers depending upon how the car is optioned. Moreover, comfort access, alarm systems etc. cause a parasitic voltage draw when parked. Parking the car for weeks or months without a trickle charger being hooked up could be killing your new batteries. The topic of battery tenders and why to use them has multiple threads on this forum. Search and ye shall find.
.